Re: [xsl] xslt 2.0 regex

[davep <davep@xxxxxxxxxxxxx>]

On 17/03/12 17:38, Brandon Ibach wrote:
> Both XSLT 1.0 and 2.0 define variable names as QNames, so they *can*
> have a ":" in them.

Agreed. My misread of the spec.
Tks Brandon.
> Ignoring that for the moment, though, Tony pointed out one consequence
> of this, but the bigger issue is that the "|" operator in regex is
> fairly low precedence, so you often need some parenthesis around the
> list of alternatives to get things right.  Your NameStartChar.re has a
> hex-char-ref-encoded "$" at the beginning, so that regex is actually
> "$[A-Z] | _ | [a-z] | ...", which means it will match "(a dollar sign
> followed by an upper-case English letter) or (an underscore) or (a
> lower-case English letter) or ...".

Which is correct (less the missing :), that's what they call the startChar?

> Actually, it might not even match that, since the "$" is a special
> character in regex, so you should escape it with a backslash to match
> it literally (though I think there are some rules which allow it to
> match literally even without the backslash, depending on what follows
> it, but best to be explicit).

+1.

> All that said, I got this to work by dropping the "$" from the start
> of NameStartChar.re and changing Name.re to:
>
> concat("\$(", $NameStartChar.re, ")(", $NameChar.re,")*")
>
> -Brandon :)

presumably because $ is within the a-z grouping....
Yes it works.

It should be possible (and simpler) to use Tony's idea \i\c+  since : is 
a valid variable name. Not a syntax I've used before I think?


Wolfgang, I was copying the syntax from the xml rec, hence the groupings.




regards

--
Dave Pawson
XSLT XSL-FO FAQ.
http://www.dpawson.co.uk